Well, never tried this or heard/read a out it, but the smoke should be so dense that even a pinhole would be revealed. Imagine a needle made out of smoke. Would you spot it? And this imaginary needle would fade out very quickly being so thin...

It would work fine for holes with diameters above a centimeter I guess....

How exactly are you getting smoke into the kite. I assume you dont want to use actual fire to create smoke all it takes is the tiniest of floating ash or ember and POP the bladder is done. So i guess . . . CO2 attached to the intake of your pump? Anyway you do it, sure seems harder than soapy water.

Peert wrote:Well, never tried this or heard/read a out it, but the smoke should be so dense that even a pinhole would be revealed. Imagine a needle made out of smoke. Would you spot it? And this imaginary needle would fade out very quickly being so thin...

It would work fine for holes with diameters above a centimeter I guess....

A friend of mine asked me to fix his bladder on a Cabrinha Kite. He said the vinil glue is not working as there is a different type of bladder in his leading edge. (board of attack). I took the bladder out and noticed its a different type of plastic, harder and kind of pink... The main air valve disconnected from the bladder and vinil glue is not woorking.... He works as a lifeguard and does not want or have the money to buy new bladders. How can I help, any ideas? Apreciate, thanks!

Sounds like your friend has an Airtime Kite ( http://www.airtimekite.com/ ) orange bladder, an after-market replacement bladder made from a composite of two different plastic films that they discontinued a few years back.
Contact Airtime, they may still have some stick-on valves for orange bladders. Regular TearAid and from the sound of it polyurethane glue won't stick to the orange bladders, different plastic.